I have a 1950 BSA ZB33A frame no-ZB31S.7016 and ZB33A.5785. I have checked with the book by Roy Bacon (BSA Singles) and it says that my type of B33 was only produced in 1950. My question is how many were produced that year of this type, and is this bike quite rare? The bike was sent to America new in 1950, and returned to England in1998. I love and ride out on this machine, dry days only. Many thanks Graham
ZB33A were made in 1950 (March - September) and 1951 (January - September) for export.
If you look at the 1950 parts book you will not find much, if any, difference between B33A and B34A engines.
Hi Julian, Thanks for this info, the engine does seem to be identical. I wonder why BSA just didn't stamp the crank cases with the B34 number in the first place. Very interesting that so few would have been manufactured during this period for export.